WD40: The WD40 domain of EED binds trimethylated lysines through an aromatic cage positioned at the top of the channel of a seven-bladed β-propeller. It is fairly promiscuous and interacts with H3K27me3, H3K9me3, H4K20me3 and H1K26me3. The structure of the EED WD40 in complex with H3K27me3 reveals an important role for the residues flanking K27me3. (1)